Method for detecting objects on a parking area

ABSTRACT

A method for detecting objects on a parking area for vehicles with the aid of image processing of images from at least two imaging sensors, detection ranges of the imaging sensors overlapping at least partially. The images of an imaging sensor whose image quality is limited by environmental conditions are weighted less strongly for the detection of objects on the parking area during image processing than images of an imaging sensor whose image quality is not limited by environmental conditions. A processing unit, a program, and an overall system for carrying out the method are also described.

CROSS REFERENCE

The present application claims the benefit under 35 U.S.C. §119 ofGerman Patent Application No. DE 102015216908.1 filed on Sep. 3, 2015,which is expressly incorporated herein by reference in its entirety.

FIELD

The present invention relates to a method for detecting objects on aparking area for vehicles, to a processing unit for carrying out themethod, to a program for carrying out the method, and to an overallsystem which is configured to carry out the method.

BACKGROUND INFORMATION

German Patent Application No. DE 10 2007 002 198 A1 describes a methodin which motor vehicles are detected on a parking area for vehicles withthe aid of video image-based object tracking.

SUMMARY

One object of the present invention is to improve the method fordetecting objects on a parking area for vehicles. Another object of thepresent invention is to provide a processing unit and a program, each ofwhich is configured to carry out the method. Another object of thepresent invention is to provide an overall system made up of imagingsensors, a processing unit and a program, the overall system beingconfigured to carry out the method.

These objects may be achieved by the method for detecting objects on aparking area, by the processing unit, by the program, and by the overallsystem in accordance with the present invention.

In a method for detecting objects on a parking area for vehicles, theobjects are detected with the aid of image processing of images from atleast two imaging sensors. The detection ranges of the imaging sensorsoverlap at least partially, and the images of an imaging sensor whoseimage quality is limited by environmental conditions is weighted lessstrongly for the detection of objects on the parking area during theimage processing than images of an imaging sensor whose image quality isnot limited by environmental conditions. During the detection of objectson a parking area for vehicles, in particular when the parking area issituated outdoors, it is possible that the imaging sensors used todetect the objects are compromised by environmental conditions. Forexample, solar radiation, or rain, or snow, or fog may impair the imagequality of one or multiple imaging sensors. During the detection of theobjects on the parking area, it is useful to weight imaging sensorswhose image quality is limited by the above-mentioned environmentalconditions less strongly than sensors whose image quality is not limitedby environmental conditions. The detection of objects on the parkingarea is thus improved.

The parking area for vehicles is made up of parking positions or parkingspaces and the associated travel paths. The parking area may be situatedoutdoors or in a building. In the latter case, this may also be referredto as a parking garage.

In one specific embodiment, the detection ranges of more than twoimaging sensors overlap at least partially, the images of more than twoimaging sensors being used to detect objects on the parking area withthe aid of image processing. The greater the number of imaging sensorsis, the better the method for detecting objects on the parking area maybe carried out.

In one specific embodiment, the limited image quality of an imagingsensor is detected with the aid of image processing. The environmentalconditions which impair the image quality of the imaging sensor changethe images of the corresponding imaging sensor in such a way that thesechanges are detectable with the aid of image processing. For example, ifsolar radiation were to degrade the image quality of an imaging sensor,this may be detected with the aid of image processing in that the imagesof the corresponding imaging sensor receive considerably strongerexposure than other images from other imaging sensors not impaired bysolar radiation. Should it thus be detected that the images of animaging sensor have a higher exposure, these images may be weighted lessstrongly during the detection of objects.

In one specific embodiment, the limited image quality of an imagingsensor is detected with the aid of a comparison of the image of theimaging sensor to a reference image of the imaging sensor recorded atanother point in time. This may be carried out, for example, when fog,snow or rain causes the contours of structures, such as lines, on theparking area to be depicted less sharply than in a reference image whichwas recorded without the above-mentioned environmental conditions. Inthis way, it is possible to identify images from imaging sensors inwhich the image quality is limited by environmental conditions, andthese images may be weighted less strongly during the detection ofobjects.

In one specific embodiment, times during which an imaging sensor has alimited image quality are calculated with the aid of the geographicallocation of the imaging sensor and/or orientation of the imaging sensorand/or date and/or time. This is in particular advantageous whencalculating times during which the image quality of an imaging sensor islimited due to solar radiation. Based on the position and theorientation of the imaging sensor, the date and the time, it is possibleto calculate all times at which the sun is positioned in such a way thatsunlight shines directly into the corresponding imaging sensor. Whensunlight shines directly into the imaging sensor, the image quality ofthe imaging sensor is limited. By calculating the times during which theimage quality is limited, it is possible to predetermine even withoutimage processing when images of an imaging sensor have a lower imagequality due to the solar radiation.

In one specific embodiment, a piece of information about an objectdetected on the parking area, in particular a position and a dimensionof the detected object, is relayed with the aid of a transmitter to areceiver in a vehicle including a device for automatically executing atleast one driving function. As a result of the relay of the position andof the dimension of the detected object on the parking area to a vehicleincluding a device for automatically executing at least one drivingfunction, this vehicle is able to take the detected object intoconsideration in its own route selection. It is thus easier for thevehicle to determine a route to a parking lot, which the vehicle is ableto follow to automatically execute at least one driving function.

In one specific embodiment, a trajectory for a vehicle is calculatedbased on the objects detected on the parking area. This trajectory isrelayed with the aid of a transmitter to a receiver in a vehicleincluding a device for automatically executing at least one drivingfunction. As a result, a fully automatic operation of the parking areais achievable in that the detected objects on the parking area are usedto calculate the trajectories for the vehicles on the parking area andnotify the vehicles about this trajectory. The vehicle may follow thetrajectory to a free parking space.

A processing unit includes connections for at least two imaging sensorsand is configured to carry out one of the methods. The connections aredata connections to process the pictures or images of the imagingsensors in the processing unit. The image processing which is used todetect the objects on the parking area thus takes place in thisprocessing unit.

In one specific embodiment, the processing unit includes a transmitterwhich is configured to relay detected objects or trajectories tovehicles. This processing unit is thus suitable for automaticallyoperating the parking garage or the parking area. A program whichincludes program code for carrying out the method when the program isexecuted on a processing unit allows the operation of an automatedparking area for vehicles.

With the aid of an overall system, made up of at least two imagingsensors and a processing unit, which is connected to the imaging sensorsand which includes a transmitter, is configured to carry out the method.

In one specific embodiment, two imaging sensors are situated in such away that the image quality of the two imaging sensors is notsimultaneously impaired by environmental conditions, in particular solarradiation.

Exemplary embodiments of the present invention are described based onthe figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a flow chart of the method.

FIG. 2 shows a flow chart of the method including further, optionalmethod steps.

FIG. 3 shows one exemplary embodiment of a processing unit.

FIG. 4 shows a further exemplary embodiment of a processing unit.

FIG. 5 shows an overall system.

FIG. 6 shows an overall system in which the image quality of a camera islimited by an environmental condition.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

FIG. 1 shows a flow chart 100 of a method for detecting objects on aparking area for vehicles. In a first method step 101, an image isgenerated in each of at least two cameras, recording areas of thecameras overlapping at least partially. In a second method step 102, theimage quality of the images is determined. The image quality of thecameras may be limited by environmental conditions, for example. Shouldthe image quality be limited by environmental conditions, this is takeninto consideration in the determination of the image quality. In a thirdmethod step 103, the images of the at least two cameras are weightedbased on whether the image quality is limited by environmentalconditions. The weighting of images of a camera whose image quality islimited by environmental conditions may be 0%, for example, and theweighting of images of a camera whose image quality is not limited byenvironmental conditions may be 100%. A different weighting of images ofa camera whose image quality is limited by environmental conditions isalso possible, for example 50%. When an image of a camera is compromisedby environmental conditions, i.e., the camera has a lower image quality,the corresponding images of the camera are thus weighted less stronglyin third method step 103 than images of a camera whose image quality isnot limited by environmental conditions. In a fourth method step 104,objects on the parking area are detected with the aid of imageprocessing of the images, the weighting of the images from third methodstep 103 being taken into consideration. The detection of objects on theparking area is carried out, among other things, in that it is detectedwhere an object is situated on the parking area, i.e., the position ofthe object is determined. Moreover, a dimension of the object may beascertained, so that it is possible to establish the surface area whichthe object occupies.

In one exemplary embodiment, more than two images are created by morethan two cameras in first method step 101, which then pass throughfurther method steps 102 through 104.

In one exemplary embodiment, a limited image quality of a camera isascertained with the aid of image processing in second method step 102.Should, for example, a camera be situated in such a way that it ispossible for solar radiation to directly strike the camera, the imagequality of the camera is limited during the times during which thistakes place. With the aid of image processing, it is possible toascertain, for example, that the image of one camera is exposedconsiderably more strongly than the image of a second camera or of areference. It is possible to infer from this that sunlight directlystruck the camera at the moment the image was recorded, whereby the highexposure was generated. By monitoring the exposure values, it is thuspossible to establish whether a limited image quality exists for acamera.

It is also possible to ascertain a limited image quality due to snow,fog or rain in that lines or objects on the parking area lose theircontour and thereby are less sharp in the images than without theinterfering environmental conditions. It is thus also possible toascertain images of cameras in which the image quality is limited byenvironmental conditions.

In one exemplary embodiment, in second method step 102 a limited imagequality of a camera is ascertained with the aid of a comparison of theimage to a reference image recorded at a different point in time.

In one exemplary embodiment, in second method step 102 the image qualityis determined by calculating times during which a camera has a limitedimage quality with the aid of a geographical location and/or anorientation of the camera and/or a date and/or a time. In particular,limited image qualities due to solar radiation may be calculated inadvance from the position and orientation of the camera, the date andthe time. In this way, it is possible to ascertain times during which itis predictable that the sun will directly strike a camera, and to weightthe images during this point in time to a lesser degree if they are usedto detect objects on the parking area.

FIG. 2 shows another flow chart 100 in which method steps 101 through104 correspond to the method steps from FIG. 1. A fifth method 105includes the relay of an object detected on the parking area, inparticular a position and a dimension of the detected object, with theaid of a transmitter to a receiver in a vehicle including a device forautomatically executing at least one driving function. By relaying theposition and the dimension of the object, the vehicle including a devicefor automatically executing at least one driving function is thus ableto plan its trajectory on the parking area.

In one exemplary embodiment, in fifth method step 105 the position andthe dimension of an object are not relayed, but based on the detectedobjects a trajectory for a vehicle on the parking area is ascertained,and this trajectory is relayed via a transmitter to a vehicle includinga device for automatically executing at least one driving function. Thedevice for automatically executing at least one driving function of avehicle may then guide the vehicle along the relayed trajectory to aparking area, which is to say a parking space, or out of the parkingspace again to the exit of the parking area.

The method may also be carried out using other imaging sensors insteadof the cameras. It is also possible to combine a camera with anotherimaging sensor in a recording range. Other imaging sensors may be laserscanners, radar scanners or LIDAR scanners. These other imaging sensorsalso supply images of the parking area whose image quality may belimited due to environmental conditions, and which may be processedfurther in the same manner in the method as images from cameras.

FIG. 3 shows a processing unit 200 including two connections 201 for onecamera in each case. This processing unit 200 is configured to carry outthe method from FIG. 1.

FIG. 4 shows a processing unit 200 which is configured to carry out themethod from FIG. 2. Processing unit 200 also includes two connections201 for cameras, and moreover, processing unit 200 includes atransmitter 202, which is configured to relay data to a vehicle.Connections 201 from FIGS. 3 and 4 may also be configured in such a waythat only one connection is present on processing unit 200, to whichmultiple cameras are connected. For example, a bus system may be usedfor the cameras, or the images of the camera may be relayed in encodedform via the one connection 201 to the processing unit.

Likewise, connections for other imaging sensors may be provided.

FIG. 5 shows an overall system for detecting objects on a parking area230. Parking area 230 is made up of parking positions or parking spacesand the associated travel paths. The parking area may be situatedoutdoors or in a building. An object, which is a vehicle 220 here, issituated on parking area 230. The object, however, may also be apedestrian or another object. A first camera 210 and a second camera 211are directed at parking area 230 in such a way that their detectionranges overlap. First camera 210 and second camera 211 are eachconnected via a data line 212 to connections 201 for cameras of aprocessing unit 200. Moreover, processing unit 200 includes atransmitter 202; processing unit 200 thus corresponds to processing unit200 from FIG. 4. Vehicle 220 is situated in the detection ranges offirst camera 210 and of second camera 211 and is thus detectable by bothcameras 210, 211 with the aid of image processing.

FIG. 6, in turn, shows a parking area 230 including a vehicle 220 andalso the further components from FIG. 5. Moreover, sun 240 is shown,along with various sun rays 241. A bundle of rays 242 strikes lens 213of first camera 210. Sun rays do not strike lens 213 of second camera211 since second camera 211 includes a diaphragm which shades lens 213of the second camera. Due to the bundle of sun rays 242 striking lens213 of first camera 210, the image of first camera 210 is considerablymore strongly exposed than if no sun rays were to strike lens 213 offirst camera 210. Due to the high exposure of the image, in secondmethod step 102 of FIG. 1 or 2 a reduced image quality of first camera210 due to environmental conditions may be determined. The images offirst camera 210 may in this case be weighted less during the detectionof the object, which is vehicle 220 here, on parking area 230 than theimages of second camera 211.

It is also possible to determine the reduced image quality of firstcamera 210 in FIG. 6 by calculating the position of sun 240 from thedate and time, and by calculating times during which a bundle of rays242 strikes first camera 210 from the position and orientation of firstcamera 210. During these times, the images of first camera 210 areweighted less strongly during the detection of objects, which is vehicle220 here, on parking area 230 than the images of second camera 211 whichis not limited by sun 240 during these times.

First camera 210 and second camera 211 are positioned in such a way thattheir image qualities are not simultaneously limited by sun rays 214.

Cameras 210, 211, like other imaging sensors which are provided insteadof or in addition to the cameras, may be attached immovably or movably.

Although the present invention was illustrated and described in greaterdetail by the preferred exemplary embodiments, the present invention isnot limited by the described examples and other variations may bederived therefrom by those skilled in the art without departing from thescope of the present invention.

What is claimed is:
 1. A method for detecting objects on a parking areafor vehicles with the aid of image processing of images from at leasttwo imaging sensors, wherein detection ranges of the imaging sensorsoverlap at least partially, the method comprising: processing imagesfrom the imaging sensors including less strongly weighting images of animaging sensor of the imaging sensors whose image quality is limited byenvironmental conditions than images of an imaging sensor of the imagingsensors whose image quality is not limited by environmental conditions;and detecting objects on the parking area based on the processed images.2. The method as recited in claim 1, wherein the imaging sensors areeach designed as at least one of a camera, a laser scanner, a radarscanner, and a LIDAR scanner.
 3. The method as recited in claim 1,wherein objects on the parking area are detected with the aid of imageprocessing of images from more than two imaging sensors, detectionranges of more than two imaging sensors in each case overlapping atleast partially.
 4. The method as recited in claim 1, wherein thelimited image quality of an imaging sensor is detected with the aid ofimage processing.
 5. The method as recited in claim 4, wherein thelimited image quality of an imaging sensor is ascertained with the aidof a comparison of an image from the imaging sensor to a reference imageof the imaging sensor recorded at another point in time.
 6. The methodas recited in claim 1, wherein times during which an imaging sensor ofthe imaging sensors has a limited image quality are calculated with theaid of at least one of: the geographical location of the imaging sensor,an orientation of the imaging sensor, a date, and a time.
 7. The methodas recited in claim 1, wherein a piece of information about an objectdetected on the parking area, including a position and a dimension ofthe detected object, is relayed with the aid of a transmitter to areceiver in a vehicle including a device for automatically executing atleast one driving function.
 8. The method as recited in claim 1, whereina trajectory for a vehicle including a device for automaticallyexecuting at least one driving function is calculated based on theobjects detected on the parking area, and the trajectory is relayed withthe aid of a transmitter to a receiver in the vehicle.
 9. A processingunit, which includes connections for at least two imaging sensors, fordetecting objects on a parking area for vehicles with the aid of imageprocessing of images from the imaging sensors, wherein detection rangesof the imaging sensors overlap at least partially, the processing unitdesigned to: process images from the imaging sensors including lessstrongly weighting images of an imaging sensor of the imaging sensorswhose image quality is limited by environmental conditions than imagesof an imaging sensor of the imaging sensors whose image quality is notlimited by environmental conditions; and detect objects on the parkingarea based on the processed images.
 10. The processing unit as recitedin claim 9, wherein the processing unit further comprises a transmitter.11. A non-transitory computer-readable storage medium storing programcode for detecting objects on a parking area for vehicles with the aidof image processing of images from at least two imaging sensors, theprogram code, when executed by a processing unit, causing the processingunit to perform: processing images from the imaging sensors includingless strongly weighting images of an imaging sensor of the imagingsensors whose image quality is limited by environmental conditions thanimages of an imaging sensor of the imaging sensors whose image qualityis not limited by environmental conditions; and detecting objects on theparking area based on the processed images.
 12. An overall system,comprising: at least two imaging sensors; and a processing unitincluding a transmitter, the processing unit connected to the imagingsensors; wherein the overall system is configured to process images fromthe imaging sensors including less strongly weighting images of animaging sensor of the imaging sensors whose image quality is limited byenvironmental conditions than images of an imaging sensor of the imagingsensors whose image quality is not limited by environmental conditions;and detect objects on the parking area based on the processed images.